September Second 4:00 pm. Here's a little more detail.

September 2 -- Prior to 4:00 p.m., New York time, clubs must reduce rosters to a maximum of 53 players on the Active/Inactive List.

September 2 -- Simultaneously with the cut-down to 53, clubs that have players in the categories of Active/Physically Unable to Perform or Active/Non-Football Injury or Illness must select one of the following options: place player on Reserve/Physically Unable to Perform or Reserve/Non- Football Injury or Illness, whichever is applicable; request waivers; terminate contract; trade contract; or continue to count the player on the Active List.

September 3 -- Claiming period for players placed on waivers at the final roster reduction will expire at 12:00 noon, New York time.

September 3 -- Upon receipt of the Personnel Notice at approximately 1:00 p.m., New York time, clubs may establish a Practice Squad of 10 players (the four designated clubs (NFC South) may sign one player to an International Practice Player Contract.) No club, including the player’s prior club, will be permitted to sign a player to a Practice Player Contract until all clubs have received simultaneous notification via the above Personnel Notice that such player’s prior NFL player contract has been terminated via the waiver system.